Virtual machines (or “VMs”) are software implementations of a machine, e.g., a computer, or a computer running an operating system, that can execute software programs. Virtual machines can for example, be used to host operating systems, applications services, and other computer programs, and can provide various functionalities via a host computer. Host computers running a virtual machine may also run a Basic Input/Output System (“BIOS”) for, e.g., initializing and testing system hardware upon boot, and for providing other functionality during computer operation.
Virtual machines can be used in various computing environments and/or by different devices. For example, a host computer running a Microsoft Windows operating system may run a virtual machine that also allows the host computer to run a single version of Linux, multiple versions of Linux, other versions of Windows or other instances of the same version of Windows, other Operating systems, or any combination of the above.